CZ504090A3 - Method of determining size of stitches on stocking knitting machines - Google Patents

Abstract

A method is described for determining the stitch loop size in stocking production machines by means of a control unit, comprising the following stages: - storing in the control unit information which for every typology and kind of yarn with which a stocking zone is to be produced represents two pairs of values, each pair of values consisting of a height of the stitch forming cylinder or height of the stitch forming triangles, and the corresponding stocking width; - selecting the width and the typology and kind of yarn for each stocking zone, to consequently determine for each stocking zone, by means of the control unit, the height of the stitch forming cylinder or the height of the stitch forming triangles on the basis of the following straight-line equation: <MATH> where l is the selected width, (h1, l1) and (h2, l2) are the two pairs of values, and h is the cylinder height; - measuring the rotational speed and the angular position of the cylinder and feeding this information to the control unit; - then feeding the commands to the stepper motor by means of the control unit.

Description

Method of determining the size of stitches. in stocking machines.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a method for determining the size of stitches in machines for producing stockings by a control unit. these machines are. high-speed machines, and subsequently determining transverse, extensibility. stockings.

The width of the variations contained in the stocking is adjusted by varying the height of the cylinder (or triangles forming the stitches). When this also moves the sinkers vertically down while the needles remain in the path determined by the control cams, these means can be varied the depth to which the needle sinks below the ejection plane of the sinker and then the length of the yarn caught by each stitch.

The cylinder position, ie its height, is set by a stepper motor. Usually, this. height is set by the operator. different experiments based on their experience. Basic. the parameters for this determination are. the type and type of yarn, while the number of needles and the speed of the yarn remain constant.

We have now found a method that allows an optimal height to be determined using a control unit using an algorithm, thereby. it will reduce the time needed for this determination and at the same time the stocking machine is more reliable, not afraid. reduces the range of operator errors.

The essence of the method of determining the size of the stitches in the stocking machines by the control unit according to the invention is that it consists of the following steps:

- storing information in the control unit for each type and type. the yarn from which the stocking is made represents a pair of values, each pair of values comprising the height of the stitch-forming cylinder or the height of the stitch-forming triangles, and the corresponding width of the stocking;

- selecting the width and type and type of yarn for each. Stocking Part to subsequently determine for each Stocking Part by the control unit the height of the cylinder forming the stitches or the height of the triangles forming the stitches based on the following, a straight line equation:

^h \ 1 - ll

- 4 where 1 is the Width selected, (h ^, 1 ^) and (h ₂ , 1 ₂ ) are two pairs of values, and h is the height of the cylinder;

- measuring the rotation speed and the angular position of the cylinder and the feed. this information into the control unit;

~ supplying commands to the stepper motor by the control unit.

AND

Experimental measurements have shown that the relationship between cylinder height and stocking width is linear, according to the graph shown. FIG. where the width · is given in centimeters and the height, the cylinder in the number of pulses to the model engine.

An analytical representation of this relationship can be obtained as the first approximation (which has proven sufficient in use) to measure the stocking width corresponding to two different heights, the cylinder. .

Let (1 ^, hp and (1 ₂ , h ₂ ) are the coordinates of the points in the plane (1, h) of Fig. 1, corresponding to these experiments.

Environmental measurement. Line equations pass through these points and then:

^h 2 “ ^h l (1) which, after substitution

Al-lj-I, a

Ah = h ^ - h ^ can be rewritten as

.. _h = - (1 - 1) + h _n (2)

11 1 11

This equation represents a functional, relationship between. the height of the cylinder and the desired stocking width.

A function in PASCAL has been developed to determine the height corresponding to a certain width. This function is based on. knowledge of the experimental data (1 ^, h ^) and (1 ^, h ₂ ) and working on generic width 1 to perform the corresponding height h according to equation (2).

To prevent the use of the fixed point function library to use the PASCAL compiler, the calculations related to equation (2) are arranged to use only integer arithmetic:

From equation (2):

£ h (1 1 1 _χ ) + h _x Δ 1 N (β)

Δ1

Of course, the numerator N of equation (3) is an integer, the ratio podíl / Δ 1 is obtained by rounding the operation according to the following algorithm :.

round (NZÓ1) = throne {(Ν / Δ1) + 0.5). = throne {(2Ν + Δ1) / 2Δΐ} -. 1.

• iř = (2N + hive) div (Al) ‘no

where round means rounding operation, throne deleting operation, and div integer division. It should be noted that the rounding function of the PASCAL language was not used as if it formed a part-arithmetic library 5 by a floating point.

The number of pulses calculated in this way to deliver to the model engine is saturated to the maximum number of pulses. .

mechanical limitations.

The PASCAL width-height conversion function is: ¹ £ width-> height conversion function} .function converti (i: byte; width: word): word;

var num, delta, deltah: integer; convl: word;

begin · with actart. zonea [i] 'do begin, convl: -maxstepr deltal: -ct12-ctll;

.delta .: = cth2-cth1;

if deltalQO then begin num: = delta * width + cthl * delta-ctll * delta ;:

convl .; = (2 * num + delta) div (2 * delta); if convl, <0 then convl: = 1;

if: convl> raaxstepr then, convl. : => maxstepr;

converti .: convl;

end else begin error: = -6 # 50; (width-setting error by editor) converti: = convl (set to valid value) end;

end;

end;

in which i = current. zone width = programmed width ctil = Width calibration ctl2 = cthl - height cth2. = coefficient 1

1.

width calibration, height calibration coefficient.

coefficient (hj (h ₂ )

The method according to the invention also makes it possible to determine the different heights of the shaped stockings. Because of this, it can often happen that the width of the stockings becomes smaller instead of remaining constant. This normally becomes an operator's intervention with each given number of revolutions to increase the height, but this is due to a more or less evident step effect. ,, t

Using the above method, for each molded part. stockings choose two widths, namely a wide width. and small width, the control unit then determines the corresponding start and end heights according to equation (1), the heights between the start and end heights are extrapolated by the control unit using an algorithm that progressively changes the width.

In this way, the height can be varied to a limit between one and the other rotational speeds. .... ...... ......

The invention also relates to a method of necessary correction of a programmed width for individual stockings. £ i

l · The width obtained on the unshaped part or the straight section of the shaped stockings is measured and if it differs from the (preselected) programmed width, the height of the cylinder or triangles forming the stitches is changed by a straight line algorithm that has the same slope as the straight line. (1) but passes through the point it has measured. width. and the predetermined height, as its. The new height for the preselected width is then determined in the manner described above.

To illustrate the control and possible correction method, use the graph in: FIG.

Line (a) is? a line calculated from * equation (1). For the programmed Width (1), the corresponding height (h) is executed.

For a control operation, a different width is measured; (1). than programmed .. *.

Then, a new working line (b) that is parallel to the original and passes through the point (1 _m , h) must be used to determine the new, corresponding height (h) to obtain the programmed width (1).

The PASCAL program below is a special way for keyboard correction. .

f data adaptation procedure for stepper-motors} procedure. adapt (var actart: article; var actsize: size);

if. flgepsil then dat_stzone [k] .epsil: = {(dat_stzone (kj.prg_width + dat_stzone (k) epsil) -dat_stzonefk] .meas_width);

newwidth: = dat_stzone [k] .prg_width + dat__stzone £ k] .epsil; dat ~ stzone £ k] .meas_width: = dat_stzonefkj.prg_width;

actsize.zonetfi] .shapesfjj.initialwidth: = newwidth; actsize.zonetfi] .shapesf j]. fin alwidth: .- newwidth; if ((actsize.zonetfi) .shapesfj + l] .initialwidth <>

actsize, zonetfi] .shapesfj + l] .finalwidth) and (j <actsize.zonetfi] .nshape)) then actsize. zonetfi]. shapes f j + l] .initialwidth: = newwidth:

j: j + 1; ) k: = k + 1;

end; j: = j + 1;

until ((k = n_stzone + 1) or (j = actsize.zonetfi] .nshape + 1));

end else .......... ........................ ..

begin if flgepsil then dat ^ stzonefl] .epsil: »f (dat_stzonefl]. prg_width + dat_stzanefl] (epsil) -dat ^ stzoneflj .meas_width);

newwidth: = dat_stzonefl] .prg_width + dat_stzonefl] .epsil; actsize.zonetfi] .initialwidthanewwidth dat_stzone fl] .meas_width: = dat_stzonef ij .prg_width;

end;

end;

end;

The operation according to the invention is described according to Fig. 3.

The control unit U is supplied with the parameters from the terminal T with a zero mark from the disk. D Sensor S and. Information regarding -. ¹ synchronization roller - · machine sensor. S ·.

The control unit supplies commands to the stepper motor M at. output shaft, mute. a disk D is mounted, which changes using a lever system. height. H cylinder C-.

.11¼ ^

V '' v

PATENT CLAIMS

Claims (4)

PATENT CLAIMS A method for determining the size of stitches in stocking machines by a control unit, characterized in that it comprises the following steps: - * jř - storing, in the control unit, for each _t type a. the kind of yarn from which the Stocking Part is made represents a pair of values, each pair of values comprising the height, the stitching rollers or the height of the stitching triangles, and corresponding to the width of the stocking; - selecting the width and type and type of yarn for each stocking part to subsequently determine, for each stocking part, the height of the cylinder forming the stitches or the height of the stitching triangles on the basis of the following line equation h - h ₁ 1 - 1 _χ ^h 2 ^h l ¹ 2 “ ¹ 1 * It 'ti where 1 is the selected width, (h ^, 1 ^) and (h ₂ , 1 ₂ ) are two pairs of values, and h is the height of the cylinder; - measuring the rotational speed and angular position of the cylinder and feeding this information to the control unit; - supplying commands to the stepper (motor) control unit. I “Μ í **** - 13 2. Method according to claim 1, characterized in that the values of both. the couples they have. be. stored in the control unit is determined by calibration, selecting two. cylinder height values and by measuring the corresponding Stocking Widths obtained. Method according to water 1, characterized in that two widths are selected for each shaped part, namely a wide width and a small width, in order to subsequently determine the corresponding. starting and ending height by the control unit based on equation (1), the heights between them are extrapolated by an algorithm by which the width changes progressively. 4. A method of modifying the height of the stitching cylinder or the height of the stitching triangles which has been determined by measuring a portion of the stocking or direct effort that value differs from a predetermined width, the height of the cylinder or triangles being modified by an algorithm representing a straight line. slope as a line of equation (1) but passing through a point with the coordinates of the measured Width and a height predetermined, this new line being used to determine a new height corresponding to a preselected width. in the method of item 1, the width obtained is unformed to the shaped part, and when